Transoral surgery for laryngo-pharyngeal cancer - The paradigm shift of the head and cancer treatment

Abstract

Transoral surgery is a less invasive treatment that is becoming a major strategy in the treatment of laryngo-pharyngeal cancer. It is a minimally invasive approach that has no skin incision and limits the extent of tissue dissection, disruption of speech and swallowing muscles, blood loss, damage to major neurovascular structures, and injury to normal tissue. Transoral approaches to the laryngo-pharynx, except for early glottis cancer, had been limited traditionally to tumors that can be observed directly and manipulated with standard instrumentation and lighting. Since the 1990s, transoral laser microsurgery (TLM) has been used as an organ preservation strategy with good oncological control and good functional results, although it has not been widely used because of its technical difficulty. Recently, transoral robotic surgery (TORS) is becoming popular as a new treatment modality for laryngo-pharyngeal cancer, and surgical robots are used widely in the world since United States FDA approval in 2009. In spite of the global spread of TORS, it has not been approved by the Japan FDA, which has led to the development of other low-cost transoral surgical techniques in Japan. Transoral videolaryngoscopic surgery (TOVS) was developed as a new transoral surgery system for laryngo-pharyngeal lesions to address the problems of TLM. In TOVS, a rigid endoscope is used to visualize the surgical field instead of a microscope and the advantages of TOVS include the wide operative field and working space achieved using the distending laryngoscope and videolaryngoscope. Also, with the spread of narrow band imaging (NBI), endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD), which are widely used for superficial cancers in the gastrointestinal tract, have been applied for the superficial laryngo-pharyngeal cancer. Both EMR and ESD are performed mainly by gastroenterologists with a sharp dissector and magnifying endoscopy (ME)-NBI with minimal surgical margin. Endoscopic laryngo-pharyngeal surgery (ELPS) was developed to treat laryngo-pharyngeal superficial cancer by modifying the ESD procedure. The concept of ELPS is the same as that of ESD, however, the resection procedure is performed by a head and neck surgeon with both hands using a ME-NBI and rigid curved laryngo-pharyngoscope. These four procedures are low cost with similar oncological and functional outcomes to TORS. TORS may be less expensive than chemoradiotherapy, but the number of hospitals that can afford da Vinci surgical systems is limited. Even in the era of robotic surgery, these four procedures will be good options for laryngo-pharyngeal cancer.

Keywords: ELPS; ESD; Japan; Narrow band imaging; TOVS.